I don't see Sony or Microsoft killing the used game industry.
As for BC, I think GTA5 has played or will play a role in PS4 BC. PS4 will be released this year, probably between October and November. GTA5 comes out late September and I don't believe it will have a next-gen version. So I don't see Sony preventing customers from playing their brand new copy of GTA5 on their $300-$400 PS4.
Damn. Tbh I was hoping to get more boycotts. I thought that most PS3's not being BC was horrible. Now I have to keep my PS2. Also if I ever want to play Amy GameCube games I have to keep the Wii because the Wii U won't.
My life remains in a standstill until I get Trails in the Sky: The Second Chapter